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Databases
Presented by Trisha Cummings
Some basics
What do databases do
 Quite simply they keep track of things
 What’s in a database
 Data are what we call raw facts or
data
 No processing has been done to them
to give them meaning
 Information is the result of processing
raw data to reveal its meaning.
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In our current “information age” we
need accurate, relevant and timely
information.
 Such information is key to good
decision making.
 Data are the foundation of
information.
 Which is the bedrock to knowledge
 Or the body of facts and information
about any specific subject.
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Data constitute the building blocks of
information
Information is produced by processing data
Information reveals the meaning of data
Accurate, timely and relevant information is
the key to good decision making
Good decision making is the key to survival
for organizations
This requires Data Management which is
simply the generation, storage and
retrieval of data
Data management requires the use of
a computer.
 A database is a shared, integrated
computer structure that stores a
collection of
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End user data – raw facts of interest to
the end user
 Metadata – or data about data in which
the end user data is integrated and
managed
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The Database Management System –DBMS
serves as an intermediary between the
user and the database.
The data structure is stored as a collection
of files and you get to them thru the DBMS
The DBMS presents the end user with a
single integrate view of the data in the
database.
Its hides the databases complexity from
users
A DBMS advantages
Improved data sharing
 Improved data security
 Better data integration
 Minimized data inconsistency
 Improved data access – thru queries
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Requests to the DBMS for data
manipulation
 Or Ad Hoc – spur of the moment queries
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Improved decision making
 Increased end user productivity
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Kinds of databases
Single User
 Multiuser
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Workgroup – smaller than 50
 Enterprise – larger than 50
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E-commerce
 Centralized – single site
 Distributed – several site
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Operational database supports day to
day operations – also called a
transactional or production database
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Data warehouse – stores data to
generate strategic or tactical
decisions
Types of Databases
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The Flat Model
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The Hierarchical Model
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Set up in a tree structure
The Network Model
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Two dimensional
Records are stored with links to other records
The Relational Model
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Most popular and a very powerful tool
Not just for storing data but also for accessing
it.
Database Design
In order to have an effective,
productive database – good design is
“mission critical”
 Needs proper structure
 Proper relationships
 Appropriate constraints
 Design databaes from existing data
 New Information Systems
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Relational Databases
Is a database composed of related
objects – primarily tables
 Allows for data to be broken down
into smaller, logical, and manageable
units
 One can still use a single query to
retrieve data spread over multiple
tables
 This is achieved thru keys.
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DATABASE
ADMINISTRATORS
What is this job like?
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The Internet and electronic commerce (e-commerce)
generate lots of data.
Computer databases that store information on customers,
inventory, and projects are found in nearly every industry.
Data must be stored, organized, and managed.
Database administrators work with database software to
find ways to do this.
They identify user needs, set up computer databases, and
test systems.
They ensure that systems perform as they should and add
people to the system as needed.
Database administrators often plan security measures. Data
integrity, backup, and security are critical parts of the job.
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On a new system, you would work with an
organization to:
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establish what the database is for, who will use it and
which other systems it will link to, for example telephony
plan its structure, showing how to organize the data (the
'back end' design), and how to find and display the
information ('front end' usability)
build a test version and check the results to iron out
technical problems, known as bugs
fill (populate) the database with new information or
transfer existing data into it
draw up plans for updating information, creating back-up
copies, reporting errors and putting in security measures.
What qualifications and experience will
employers look for?
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For most DBA jobs, you would need to know how
to use structured query language (SQL) along with
database management systems (DBMS), which
include:
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RDBMS (relational database management systems)
OODBMS (object-oriented database management
systems)
XML database management systems.
There are different ways to gain this knowledge
but employers often look for previous experience
in computing. This would normally be in the form
of an IT support, programming or web
development background.
Duties:
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The DBA must be able to work independently as well as in a
team environment.
Develop data model describing data elements and how they
are used, following procedures and using pen, template or
computer software.
Develop standards and guidelines to guide the use and
acquisition of software and to protect vulnerable
information.
Establish standards, criteria, and guidelines with respect to
design implementation, testing and use of data for an office
or department.
Modify existing databases and database management
systems or direct programmers and analysts to make
changes.
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Plan, coordinate and implement security measures to
safeguard information in computer files against accidental or
unauthorized damage, modification or disclosure.
Examine and recommend for approval, procedures in
database management system manuals for making changes
to database.
Examine and recommend for approval, project requests
describing database user needs to estimate time and cost
required to accomplish project.
Review workflow charts developed by programmer analyst to
understand tasks computer will perform, such as updating
records.
Select and enter codes to monitor database performance
and to create production database.
Specify users and user access levels for each segment of
database.
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Test programs or databases, correct errors and make
necessary modifications.
Write and code logical and physical database descriptions
and specify identifiers of database to management system or
direct others in coding descriptions.
Approve, schedule, plan, and supervise the installation and
testing of new products and improvements to computer
systems, such as the installation of new databases.
Develop methods for integrating different products so they
work properly together, such as customizing commercial
databases to fit specific needs.
Identify and evaluate industry trends in database systems to
serve as a source of information and advice for upper
management.
Maintain and revise data dictionary.
 Train users and answer questions.
 Help users with problems.
 Work as part of a project team to
coordinate database development
and determine project scope and
limitations.
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You may have extra duties like supervising
technical support staff, training users and
producing performance reports for IT managers.
In a senior position you would normally be
responsible for strategic planning, information
policy, budgets and managing client relationships.
Other IT professionals like analysts, programmers
and IT project managers, would normally work
closely with you on projects.
Educational needs
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Associate in Arts in Information Systems
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Major Component
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CIS
CIS
CIS
CIS
CIS
CIS
CIS
CIS
CIS
CIS
CIS
110
111
155
175
210
212
219
222
242
276
209
Computer Programming Design
Introduction to Relational Database Management Systems
UNIX Operating System
Introduction to Networking
Systems Analysis and Development
System Modeling Theory
Database Management Systems
Computer Ethics
C++ Programming
SQL Programming
Web Page Development I
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Bachelors' Degree – all of the AS courses plus a
Concentration in: Database Management
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CIS
CIS
CIS
CIS
CIS
CIS
276
305
434
444
474
499
SQL Programming
PL/SQL Programming
Database Fundamentals I
Database Fundamental II
Data Warehousing
Senior Seminar in Computer Information Systems
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Software development companies also
offer database certification programs.
Examples include:
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Microsoft Certified Database Administrator
(MCDBA)
Sybase Adaptive Enterprise Server (Developer
and Administrator pathways)
Oracle PL/SQL Developer, and 9i and 10g
Administrator (Associate, Professional and
Master levels)
IBM DB2 and Informix certification.
Resources
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http://portal.cuny.edu/cms/id/cuny/documents/jobposting/023097.
htm
http://www.bls.gov/k12/computers01.htm
http://www.learndirectadvice.co.uk/helpwithyourcareer/jobprofiles/profiles/profile779/
Database Processing – Fundamentals, Design, and Implementation
by David M Kroenke – 10th edition ©2006, published by Pearson
Prentice Hall.
Teach yourself SQL in 24 hours –by Ronald R Plew and Ryan K.
Stephens - 3rd edition - published by SAMS
Database Systems – Design, Implementation and Management –
Peter Rob and Carlos Coronel – 8th edition – Thomson Course
Technology
http://www.strayer.edu/campus_catalog/VA/all/alexandria/informat
ion_systems/associate_in_arts_in_information_systems
http://www.strayer.edu/campus_catalog/VA/all/alexandria/informat
ion_systems/BSIS